In 2021, according to the Australian Bureau of Statistics (latest report as of October 2021) there were 4,248 multiple births representing 1.5% of all births (309,996) in Australia. This comprised 4,185 pairs of twins and 63 sets of triplets and higher order multiples.
In Australia, twins happen in 1 in every 80 births. This means that 1 in 40 Australians is a twin.
As of 2021 the birth rate for twins in the U.S. was 31.2 per 1,000 live births.
Twin births account for approximately 3 percent of live births in the United States. Barring pregnancies that result from assisted reproductive technology, dizygotic twins are far more common than monozygotic twins and account for 70 percent of all twin gestations.
Asian Americans and Native Americans have the lowest rates for twins. White people assigned female at birth have the highest rate of higher-order multiple births (triplets or more). This is especially true for those older than 35.
Vietnam was the country with the fewest twins (6.2 per 1,000 births) and Benin was the country with the most (27.9 per 1,000). Over time, some of these developing countries saw increases in twins, but some saw decreases and some stayed the same, with any changes tending to be small.
The rate keeps rising for (naturally) two big reasons. More twins are being born now than ever before. Parents are increasingly using in-vitro fertilization and deciding to have children later in life. The twin rate could continue to go up as more nations push these factors higher.
According to the Office on Women's Health , women who are aged 30 years or older are more likely to conceive twins. The reason for this is that women of this age are more likely than younger women to release more than one egg during their reproductive cycle.
Older age– Women over 30 have a greater chance of multiple conception. Many women today are delaying childbearing until later in life, and may have twins as a result. High parity – Having one or more previous pregnancies, especially a multiple pregnancy, increases the chances of having multiples.
How Common Is Having Twins? Multiple births — which include twins, triplets, quadruplets, and more — have become more common in recent years because more couples are turning to fertility drugs and IVF treatments to help them conceive. In the United States, twins account for about 3 percent of live births.
The chances of having identical twins is relatively rare. For every 1,000 births, identical twins happen every 3rd or 4th. Although, the use of fertility treatments will increase the risk of having identical twins. Identical twins actually make up 0.95% of pregnancies that were conceived with treatment.
Some names for these are: Twins for 2 fetuses. Triplets for 3 fetuses. Quadruplets for 4 fetuses. Quintuplets for 5 fetuses.
On Canadian soil, more than 6,000 sets of twins are born each year, contributing to the current rate of multiple births, which is roughly one in 31. A multiple birth is defined as a birth in which two or more babies are delivered from a single pregnancy on the same occasion.
Identical, or monozygotic (MZ), twins have 100 percent of their genes—including those that influence risk for alcoholism—in common, whereas fraternal, or dizygotic (DZ), twins share (on average) only 50 percent of the genes that vary in the population (see figure). Common Environmental Sources.
Factors that increase the chance of twins include: consuming high amounts of dairy foods, being over the age of 30, and conceiving while breastfeeding. Many fertility drugs including Clomid, Gonal-F, and Follistim also increase the odds of a twin pregnancy.
Having identical twins is not genetic. On the other hand, fraternal twins can run in families. Genetics can definitely play a role in having fraternal twins. For example, a woman that has a sibling that is a fraternal twin is 2.5 times more likely to have twins than average!
It's equally unsurprising that a Danish study found that twins are less likely to get married than non-twins. As twins have a partner from birth, the study suggests that they may not have the same desire for marriage as singletons.
In fact, one British study tested ESP potential among identical twins and found that they were correct about 25% of the time, the same as any other siblings. There is one particular power though which twins possess, longevity. Fraternal twins live longer than singletons and identical twins longer still.
It has been widely assumed that there has been an increase in twins over the years, largely attributed to fertility treatments. But the increase in the multiple birth rate means not just more twins, but also higher order multiples, such as triplets, quadruplets and the like.
The very low natural twinning rates of 6–9 per thousand births previously observed in some East Asian countries turn out to be the dominant pattern in the whole South and South-East Asian region.
South Korea has the world's lowest fertility rate, a struggle with lessons for us all. A woman holding her daughter looks at a view of Seoul in 2019. The fertility rate in South Korea, which has the world's lowest rate, hit 0.78 in February.
Indeed, analysis on the offspring of twins shows that they are not exceptionally fertile when compared to the rest of the population.